Printing press



April 16, 1929. R, HORN 1,109,575

PRINTING PRESS Filed Oct. 28, 1924 Patented Apr. 1 6, 1929.

umrlazn STATES 1,109,575 PATENT OFFICE.

RUDOLI HORN, OF DRESDEN, GERMANY.

PRINTING iPRESS.

Application filed October 28, 1924, Serial No. 746,270 and in Germany October 81, 1923.

The present invention relates to that class of printing-presses (off-set press) in which, for the production of impressions or prints on paper, webs, sheet-metal plates or the like,

' 5 at least and without any exception, one cylinder carrying zinc-plates or forms carrying the original or printing picture and one cylinder stretched with rubber are arranged. The cylinder carrying or stretched with zinc- .10 plates or blankets operates together with the rubber cylinder and transfers the inked original or printing picture to the rubber cylinder mentioned, from which it is hereafter printed onto the paper, web or the sheetmetal plates.

The present lnvention has for its object to fully dispense with the cylinder carrying the zinc-plates and to directly transfer the print-.-

4 more the necessary intermediate transfer from zinc to rubber necessary for the print- A ing-pressesknown up to now is fully dispensed with, whereby a more intensive clearness of the picture is ensured also. Furthermore, the working of the printing-press will not onl be an easier one by dispensing with said cy inder carrying zinc-plates, but it can even run with a higher printing-speed also.

The object of the present invention is represented in the drawing annexed by way of example in two constructions. Fig. 1 is a rotating rubber rinting-press for printing separate sheets, ig. 2 a press for printing a continuous pa er-shect or band.

a is the rub er cylinder stretched in a known manner with rubber plates 6. Instead of rubber, linoleum or other flexible nonmetallic plates may be used. The rubber plates are prepared, for instance by roughening and treating them with acetic acid insuch a manner that practice shows they obtain qualities equal to those. of the zinc-plates or stones heretofore used for printing purposes, in other words that said plates absorb water and fatty inks. The print-picture is then transferred to the plates prepared in the manner indicated. The wetting-apparatus 0 serves to moisten the so called empty points of the rubber plate on which, therefore, is no printpicture, so that theinking rollers d deliver their fatty ink to the printing-picture itself only, whereas the empty points of the rubberplat-e moistened by the wiper-rollers do not allow the ink to adhere. The sheet is applied to the printing cylinder 6 in a known manner, printed by the rubber cylinder and hereafter lifted up to the device f; One rubber-plate only or more than two such plates may be ar-' ranged on the cylinder a.

Fig. 2 represents a rotating rubber printing-press in which, the paper is printed simultaneously on both sides. Forthis purpose there are two cylinders a a provided with rubber plates. These cylinders work together and are provided with one or more proper inking apparatus (l (Z and wettingapparatus 0 0 If it is intended to print one surface of the paper only the inking and wetting apparatus of one cylinder are disengaged, so that this cylinder forms the counter cylinder for the second cylinder.

It is preferable to transfer the printing pictures to the rubber-web from the original picture or from the reprint only if the rubberwebs are stretched under tension around the cylinder already. This can be performed for instance by inking in advance the reprint or the original of the printing-picture present for instance on the zinc-plates and then allowing it to run through the rubber printing 35 press like a sheet to be printed. The inked printing picture then prints on the rubberplates whereby the rubber linings are transformed into printing plates to be wetted and inked.

What I claim is:

1. In a rotary printing press for direct lithographic printing, a printing cylinder, an impression cylinder, inking rolls, and a plate of flexible, soft and resilient material on the said rinting cylinder, the. said printing plate eing repared for direct application thereto of in from the inking rolls and for printing directly therefrom on a sheet passing between the same and the impression cylfinder.

2.- In a rotary printing press for direct lithographic printing, a rlnting cylinder, an impression cylinder, in ing rolls, damping rol s, and a plate of flexible, soft and resilient material stretched on the said printing cylindcr,'the said )late of flexible, soft and resilient material. e'ing prepared for taking ink directly from the printing rolls and moisture from the damping rolls and printing directly therefrom on a sheet passing between the same and the impression cylinder.

3. In a rotary printing press for direct lithographic printing a printing cylinder, an nnpresslon cylinder, inking rolls, and a plate of flexible, soft and resilient rubber on the said printing cylinder, the said plate of flexible, soft and resilient rubber being prepared for directly receiving ink from the inking rolls and for printing on a sheet passing be tween the same and the impression cylinder. 4. In a rotary printing press for direct lithographic printing, a printing cylinder, an impression cylinder, inking rolls, damping rolls, and a plate of flexible, soft and resilient rubber stretched on the said printing cylinder,- the said plateof flexible, soft and resilient rubber being prepared for receiving ink direct from the inking rolls and moisture from the damping rollsand for then printing directly therefrom on a sheet passing between the same and the impression cylinder.

In testimony, that I claim the foregoing as my invention, I have signed my name this 8th day of October, 1924.

- RUDOLF HORN. 

